Cold-sawing machine.



c. A. BIRTH.

GGLD SAWING MACHINE.

APPLIUATIONIILED MARJQ. 1912.

Patented Dec. 17,1912.

" UNTED STATES A'rmi]ENT onnrcii.

om ALBERT BIRTH, or CANNSTATT-STUTTG'ART, GERMANY, AssIGNon 'ro FORTUNA- To all whomt may'concem:

WERKE ALBERT rIEIIBTH, 0F GERMANY.

Specication of Letters' Patent.

Y COLD-SAWING MACHINE. u

Application-med March 19, 1912. Serial No. l684,829.

Be it known that I, vCARL ALBERT HIRTH,

a citizen of `the German Empire, residing;

in Cannstatt-Stuttgart, in the Kingdom of Wurttemberg, in said Empire, have invented certain new' and .useful `Improvements in Cold-Sawing Machines, of which the .following is a specification. v 'y This invention relates to certain improvements in cold sawing machines by which rectangular and oblique cuts can be accu'- rately made through the work-piece as the same is held inone position or the other by the jaws of the vise closely and reliably to the blade of the cutting saw.

Hereto'fore the jaws ofthe vise between which the work-piece wasclamped were provided with cheeks which were centrally pivoted to the upper portions of sleeve-shaped nuts that were moved toward or away from` each other by a screw-spindle having a right and left-hand screw-thread. When the jaws were turned from their position at right angles to the saw-blade into an oblique position thereto, the front-end of one jaw was` moved away fromthe lsaw-blade while the front-end of the other jaw was moved closer lbe necessary to shorten the jaws, which however would bring the ends of the jaws, when in their rectangular position to the blade, too far away from the same so that when they are turned on their pivots into an obliqueposition the front-ends of the jaws would begmoved too far away from the blade so that .the work-piece could not be held with the desired degree of certainty close to the ,plane of cut and that furthermore by thel oblique clamping of the workpiece a turning momentum was exerted on the same by which a tendency was imparted to the jaws to returny into their normal position at right angles to the blade.

The object of this invention is to obViate the objections referred to and the invention consists in so arranging the jaws of the vise that the fastening'bolts are not used as turning on pivot-bolts, but are located in arc-shaped slots Vof their cheeks sothat the turning'aXes of both jaws are close to the faces of the jaws whereby the frontends of the jaws when placed i-n an oblique position to the blade are both brought close to the, vertical plane rof the blade.

The invention consists further of providing means for shifting the supporting screwspindle of the vise in a longitudinal direction and then locking it in the proper position according to the angle of Obliquity to whjph the jaws have to be set toward the bla e.

In the accompanying drawings, Figure 1 represents a side-elevation of my improved cold-sawing machine, Fig. 2 a plan-view of Fig. 1,' Fig. 3 an end-viewof the same, and

Figs. 4 and 5 show detail Sectional elevations j of different means for providing for the longitudinal shifting of the screw-spindle.

Similar letters of reference indicate corresponding parts throughout the several figures of the drawin s.

Referring to the rawings, a represents the saw-blade, and b the bow for the same. The bow b is reciprocated in the usual well known manner by means of a connectingrod c from a crank-disk o to which motion is imparted by a suitable power-transmission. The bow is provided with a longitudinal guide-piece c2 which is-guided in stationary ways e3 of the supporting-frame of the machine, as shown in Figs. 1 and 2.

"Figs 1 and 2 show the position of the bow in 1ts median position.

d and e represent the jaws .of the vise between which thework-piece is held for the action of the saw-blade a. The jaws d and j Y. e are so arranged that when they are adjusted at right angles to the path of the blade, the oint where the cut is to be made on the wor -piece is located midway of the stroke ported by means of sleeve-shaped nuts g and la on the spindle f'which is provided with right and left-hand screw-threads by which the jaws are moved simultaneously toward or away from each other according to the direction of the turning motion of the screwspindle.

of the blade. The jaws of the vise are sup- ,60 hand thread of the screw-spindle.

lThe cheeks d and e of the jaws d and e are made with cylindrical rear-faces d', e by which they .can be adjusted on the correspondingly-sha ed abutments g', h of the nuts g and h, t e axes of the cylindrical cheeks bei located in or as close as possible to the aces of the jaws. In the cheeks of the jaws d and e are arranged arc-shaped slots o in which the supporting-bolts g2 and h* of the'4 jaws are located. vThis arrangement ts that the front-ends of the jaws when 1n their middle'position at right angles to the blade, are located closely to the blade,

v while neitherA oneof the jaws on turning the Same, into an oblique position to the blade, is placed ,within the path of the same, whereby the tendency of the jaws to move into a position at rghtangles to the saw, is neutralized, and the distance of the jaws the change of position producing in both aws near y the same distance from the sawblade, as mdic'ated by the dotted lines in Fig. 2.

The sleeve-shaped nuts g and h are guided in ways 'w of the frame of the machineand the spindle supported by the nuts. This arrangement prevents any bending of the spindle in upward direction by a too forceful clamping of the work-piece between the aws. J The jaw d is provided at its rear-end with an interiorly-threaded eye for receiving a screw-bolt d* which serves as a stay for the jaws when very short pieces have to be clamped between the same so as to prevent the converging of the rear-ends of the jaws.

When the jaws are adjusted into an oblique position, as indicated in dotted lines iny Fig. 2, the point of cutting of the blade would be considerably to one side of the middle of the stroke of the saw, which is open to the objection that the blade will onl cut during a part of its entire length an that its stroke would not be fully utilized. The diminution of the useful length of the saw-stroke is equal to double of the shifting distance of the cut, so that thereby the eiectiveness of the saw-blade would be considerably diminished. Asthe stroke of the saw cannot be changed except by changing the entire construction of the machine, it is therefore necessary to bring the obliquely-adjusted work-piece to the middle of the saw-stroke for producing the effective action of the machine.- For this purpose the entire machine would have to be taken apart and the jaws of the vise be adjusted one on the right-hand and the yother on the rlleflts would be however, very tedious and tiresome, and besides inaccurate, inasmuch as the size of the adjustment cannot be estimated beforehand with absolute certainty. 35 The same inaccuracy would occur when the from the saw rendered as small as possible,l

in Fig. 4. Furthermore, the adjustment jaws would be adjusted by means of any other device on the screw-spindle, such as, for instance by means of a split-nut or any other adjusting device between jaws and nuts. This would add another objection, namel that these adjustable fastening devices ave to receive the entire pressure of the device. lThe present invention obviates these objections by leavin the 'aws of the device on the screw-spin e an adjusting the parts in their entirety. This has the advantage that the adjustment can be accomplished ina quick and simple manner, that the pressure of the device is not. -required to be taken 'up by the adjusting-means, and 8o especially that. the Qwork-piece can be clamped and finally adjusted to the required oblique position after it has been ascertained to what degree the adjustment would be necessary. The arrangement forl accomplishing th1s purpose-provides that the `screw-spindle has at its outer end which pro'ectsbeyond the supporting-frame, an annular groove z' that 1s engaged by an end-plate -k provided with a recess lc that enters into the groove i. As the device has to be set to a number of different oblique angles which correspond to 15, 30, 45, etc., a plurality of additional v annular grooves m, n, o' are arranged in addition to the annular groove i, so as to permit thereby the different oblique positions -of the vise accordin to the, angles referred to. The plate lc is 'ivpted to one of its fastenmg-screws p an provided-with. a recess r which lits over the other fastening-screw g, as shown in Fig. 3. This sameaidea can be carried out indifferent ways. The screw- J spindle f could for instance, instead of being provided with several annular grooves at different distances from each other, be provided with regular ring-shaped teeth f which are en aged by a correspondinglyshaped geareel f2 located at right angles thereto for adjusting the spindle as shown could be made by a screw-thread f3 on the spindle as shown in Fig. 5, but in this case it would be necessary to make the nut required for this thread stationary during the adjustment of the jaws of the vise toward or away from each other, that thereby a longitudinal shifting of the screw-spindle itself should not take place.

I claim:

1. .A cold-sawing machine, comprising means for reciprocatin a saw-blade, a screw-spindle having a rlght and left hand screw-thread, a vise formed of two jaws having straight parallel faces and cheeks. with curved rear-faces, sleeve-shaped nuts on the screw-spindle having abutments with curved faces engagin and corresponding in curvature to the rearaces of the cheeks, and means for adjusting the jaws into an oblique position relatively Ato the saw-blade, the 130 thread, a vise formed of two jaws having cheeks with curved rear-faces and arcshaped slots, sleeve-shaped nuts having abut-ments with curved faces engaging and corresponding in curvature to the rear-faces .of the cheeks, and pivot-bolts passing through the arc-shaped slots of the cheeks,

the axes of the curved engaging faces of the cheeks and abutments being located in the faces of the jaws.

3.` A cold-sawing machine, which comprises a reciprocating saw-blade, a vise having jaws obhquely adjustable with respect to the saw-blade, a screw-spindle supporting the jaws of the vise and provided with ringshaped grooves at the outer end, and means for supporting one ci the grooves of the spindle and locking the s indie after iongltudinai displacement of the same.

e., A cold-sawing machlne, comprising a reciprocating saw-blade, a vise formed of two jaws, a screw-spindle having right and left hand screw-threads 'for adjusting said jaws and ring-shaped grooves at the outer end of said spindle, means whereby the jaws may be adjusted at an oblique angle to the saw-blade, a locking plate provided with a recess for engaging one of said grooves, and means for securing said plate in engagement with the oove. y

ln testimony, that claim the foregoing as myinvention, I have signed my name in presence of two subscribing witnesses.

CARL ALBERT HIRTH.

Witnesses ERNEST ENTENMANN, FRIDA KLAIBER. 

